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BCLASS_QUERY_TAG_CALLBACK callback function (batclass.h)

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BatteryMiniQueryTag returns the current battery tag.

Syntax

BCLASS_QUERY_TAG_CALLBACK BclassQueryTagCallback;

NTSTATUS BclassQueryTagCallback(
  [in]  PVOID Context,
  [out] PULONG BatteryTag
)
{...}

Parameters

[in] Context

A pointer to the context area allocated by the miniclass driver for the battery device.

[out] BatteryTag

A pointer to a caller-allocated variable in which the miniclass driver returns the battery tag.

Return value

BatteryMiniQueryTag returns one of the following:

Return code Description
STATUS_SUCCESS
 A battery is currently installed.
STATUS_NO_SUCH_DEVICE
 No battery is present.

Remarks

The battery class driver calls BatteryMiniQueryTag to get the value of the current battery tag. If a battery is present, BatteryMiniQueryTag should return the tag in BatteryTag and return STATUS_SUCCESS.

Each time a battery is inserted, the miniclass driver must increment the value of the tag, regardless of whether this is a new battery or the same battery that was previously present.

If no battery is present, or if the miniclass driver cannot determine whether a battery is present, it should return STATUS_NO_SUCH_DEVICE and set the value of the tag to BATTERY_TAG_INVALID.

Requirements

Requirement Value
Target Platform Desktop
Header batclass.h (include Batclass.h)
IRQL PASSIVE_LEVEL